Furnace grate



July 10, 1928,

' 1,676,349 E. B. PRIEBE FURNACE GRATE Filed Sept.25. 1922 5 Sheets-Sheet 1 v Q J v E. B. PRIEBE FURNACE GRATE July 10', 1928.

5 Sheets-Sheet 2 Filed Sept. .25. 1922 July 10, 1928.

E. B. PRIEBE FURNACE GRATE 5 Sheets- Sheet 5 Filed Sept 25. 1922 171122721577 WE-IPMLM 6 be. W1) Kww va WW6 E. B. PRIEBE FURNACE GRATE July 10,1928.

5 2 t p e s d e l i 1,7 6,349 E B. PRIEBE I FURNACE GRATE Filed Sept 25, 1922 5 Sheets-Sheet. 5

Patented July 10, 1928.

ERNEST IB. PRIEBE, OF INWOOD, NEW YORK.

FURNACE GRATE.

Application filed September 25, 1922. Serial No. 590,446.

This invention relates to furnace grates and more particularly to the twyer construction formingthe fuel bed support of a furmace and supplying air of combustion to the fuel.

The general objects are to afford a furnace grate construction with better efficiency in regard to air supply and otherwise, durability, economy and low cost of construction and ease of replacement of damaged mem bers.

A further object is to afford a twyer construction especially adapted to various typesof multiple retort underfeed furnaces, for example the type in which the retorts of the grateare stationary, exemplified by the well known Taylor stoker, or the type in which the retorts are reciprocating, exemplified by the well known Riley stoker, in either case the twyer construction of this mvention being intended to rest over the air boxes between the retorts, in a relatively stationary manner, that is, the twyer system havlng no movement unlesswith the retorts.

Other objects of the present invention are to prevent the shifting of fuel and ashes from the fuel bed into the air boxes between the retorts, to protect the exits of the twyer a ertures from being closed or clogged by the uel; and further ob ects and advantages will be explained in the hereinafter following description of one or more embodiments, or will be apparent to those skilled in the subject. To the attainment of the above mentioned objects and advantages, the present invention consists in the novel'furnace grate and twyer system, and the novel features of construction, combination. arrangement, mechanism and detail, herein illustrated or described.

In the accompanying drawings F gure 1 is a general side elevation of the interlor parts of a furnace of the stationary retort or Taylor type embodying the present 1nvention seen from the left side of,F1g. 2, and showing twyer constructions 22 and 23.

Figure 2 on a larger scale, is a transverse section taken substantially on the line 22 of Figure 1.

Fig. 2 is a similar view showing modified twyer constructions 21 and 24.

Figure 3 is a face elevation of one of the twyers 22 looking from the furnace rear.

Figure 4 is a right elevation of the twyer of Figure 3. Figure 5 is a horizontal section taken on the line 55 of Figures 3 or 4. Figure 6 is a top view of the twyer. Figure 7 is a perspective view of the same.

Figure 8 is a view similar to Figure 4 but showing two of the twyer members in operative relation, and substantially corresponding to a portion of Figure 1.

Figure 9 is a perspective view of a detached twyer member of the form 21.

Figure 10 is a partial cross section showing the invention applied to the reciprocating retort or Riley type of furnace and with additional structural features indibated, this figure indicating one of the twyer-s 21 and a still further form indicated as 25. Figure 11 is a partial left face view of the wall shown in Figure 10.

Figure 12 is a face elevation, lookin from the rear, ofthe detached twyer bar 0 form 23, 24 or 25, all one sided structures. Figure 13 is a side elevation thereof. Figure 14 is a horizontal section taken on the line I l-14 of Figure 12. Figure 15 is a top view of the twyer bar shown in Figure 12, so and Figure 16 is a perspective thereof. Figures 12 to 16 correspond to Figures 3 to 7 inclusive, for the diflerent twyer form.

Some of the features of novelty in the present structure may be said to be lmprovements based upon the structure of my prior Patent 1,360,250 of November 23, 1920 and other features are similarly based on the disclosure in a pending application filed September 26, 1921, Serial No. 503,334, by W. C. Drake and myself; the present case showing yet further features having no relation to these prior structures.

The drawings show the'usual furnace front wall 26 and at the rear a bridge wall 27 and side walls 28. At the front, exterior to the furnace, is the fuel hopper 29 which discharges beneath to the casing or ram box 30 in which operates the ram or infeeding pusher 31. The ram is shown as reciprocated by a connecting rod 32 extendin from a crank 33 on a power shaft 34. T e rod 32 is connected to the upper'end of an oscillating bar 35 fulcrumed at 36 and serving to operate certain mechanisms, for example, by a rod 37 reciprocating a distributing member or pusher 38 located in the retort, to be described. It will be understood that the elements 30 to 38' are duplicated for each retort of the furnace,

:The fuel which is thrust inwardly by the ram 31 passes throughthe throat 39 beneath the front wall and forms and maintains a fuel bed indicated by the line 40 in Figures 1 and 2. The fuel rests upon the furnace grate which consists mainly of alternate air boxes 41 and retorts 42, which are prefer- I rearwardly in the retorts.

till

In Figure 1 is shown a wind box 45 having an uptake 46 leading into the air condult 47 which extends beneath and furnishes air to all of the air boxes 41. The air is also supplied from the uptake to a chamber 48 which conducts air to the supplemental grate, to be mentioned. A damper 49 in the uptake 46 is controllable by exterior damper rod 50 to regulat the ressure of the forced draft.

To the rear 0 the series of retorts and air boxes is shown a supplemental or terminal grate 51 which may be reciprocated from the oscillating bar 35 by means of rod 52, slide 53 and rock arm 54. The advancing fuel bed assing from the grate section 51 is received y a dumping grate 56 operated automatically and periodically in any usual manner by mechanism 57.

Coming now to the twyer structures overlying the several air boxes ll, it was already stated that I herein show several modifications or variations of form of twyers. Thus the twyer form 21 is shownin Figure 2 and on a larger scale in Figure 9. The twyer form 22 is shown in Figures 1 and 2 and in Figures 3 to 8. The remaining three twyer forms 23, 24 and 25 are side wall or onesided twyers, resting over the extreme air boxes. Form 23 is shown in Figures 1 and 2", form 24: in Figure 2*, form 25 in Figure 10; and Figures 12 to 16 substantially illustrateall three of these.

Features of novelty of the present invention are embodied in all of the disclosed twyer forms and could be embodied in a great many further forms. For convenience of description ll will first describe the twyer form 22, which is most thoroughly illustrated, pointing out features which are. common to the other forms and those which are characteristic of form 22. In whatever form the improvements are embodied it will be understood that the complete twyer system involves an extended series or bank of twyer aeraere members or blocks overlying each air box and extending from side to side thereof. The series of members so' assembled above each air box may be of diflierent forms and li in various relative positions while embodying certain features of the present invention. I prefer, however, that the individual twyers or blocks shall be arranged in positions outstanding or upstanding from .the edges of the air box in the manner explained in my said patent so that each memher or block rests its weight upon the air box as a support, while adjacent members are in mutual contact, giving a continuous grate surface, withof course air or twyer openings leading directly into the fuel bed.

As in my prior patent the outstanding twyer members are herein shown as stacked in mutual contact or engagement. In describing a twyer member it is to be under stood that the length of the member corresponds with its up and down dimension, as will be clear from Figures 1 to d, and the width may be considered as the transverse dimension, as seen in Figures 2 3, 5, 6' and 7, corresponding with the width of the air box, Each twyer member 22 or 21 is preferably a single integral piece of cast iron, excepting for the separate cap pieces of member 22. Each twyer member is interiorly hollow so as to receive the air from the air box and conduct the same to the twyer openings, or passages. In twyers 21 and 22 the member is composed of two opposite portions or side bars 60 60 which I prefer to have converging upwardly, as in my said patent, so as to a ord retorts which flare upwardl Each retort 4:2 ma be considered as including the floor 14:, t e imperforate side walls 13 and the opposite diverging twyers, thus constituting a retort flaring upwardly. In

form 22 the side bars 60 do not meet at their J upper ends but fall short of meeting, leaving a space, to be engaged by special cap pieces, while in form 21 the opposite side bars meet integrally at the top, as best seen in Figure 9.

Each of the difierent twyer forms is provided with a downward lug or lugs 61 or 61* for the purpose of positioning the same in respect to the air boxes or members assollU ciated with the air boxes. An integral connecting web 62 or 62' is shown extending transversely from one side bar to the other, and these webs are suficiently thin to permit .free passage of air upwardly between them. Each web is shown perforated at-63 or 63*, this being for the purpose of placing a securing bolt through all the perforations in order to hold the twyer members securely in place. Such bolt 64: is indicated in F igure 1. r

lit will thus be seen that each twyer member faces the adjacent members forward and to the rear of it, and these faces or front and rear surfaces of the members or side bars are 7 constructed to afford lateral twyer openings or passages directed into the fuel in the retorts. These openings are herein shown substantially horizontal, substantially equal in size and substantially uniform in diameter, but in all these respects obviously the parts could be redesigned, within the prin ciples of the present invention.

According to the present invention the twyer openings are produced by means of interpenetrating ribs at the forward and rear faces of the twyer members or bars. The ribs, at the one side, are staggered with respect to those at the other and the ribs and spaces are of such relative proportions that each rib of one twyer member will penetrate the space between two ribs of the adjacent member without contacting them,

but leaving air passages of substantial size.

Thus Figures 1, 2 and 3 to 8 show front ribs and rear ribs 66 of two adjacent twyer members. the same interpenetrating so that no rib contacts any other rib, but each rib contactsthe body or side bar of the adjacent twyer, thus giving air passages of substantial dimension above and beneath each rib. See especially Figures 1 and 8. This principle of structure pertains to all of the variations of twyer member herein illustrated.

It will be noticed that each twyer member 22 is provided with three front ribs 65 and three narrow ribs 66 and a deeper bottom rib 67 at the rear, the arrangement giving six apertures 68 between each two twyer bars at each side of the structure. This system, therefore, is of value in its adaptability to afford a considerable number of apertures. My prior patent shows but three apertures between each pair of twyer bars.

Moreover, a very valuable feature results, namely, in the non-sifting qualities of the twyers. Any powdered fuel or ash tending to enter a twyer opening from the retort finds itself resting upon one of the ribs 65 or 66. Air is constantly passing outward above each rib and therefore the siftings are constantly blown out and are not permitted to pass into the interior of the twyer member or air box. The arrangement is very effective. Moreover, the siftings cannot pass downwardly, little by little, and finally find their way into the air box because each rib 65 or 66 contacts against the body of the side bar of the adjacent twyer member. Moreover, any particle would have to pass downwardly through a zigzag path around the ends of all of the ribs and finally pass the deep rib 67 at the bottom, a practical impossibility, as every particle of siftings would be subject to be blown outwardly into the fuel bed at every stage of this movement.

Each rib 65 or 66 may be slightly broader at its 'base than at its extremity for purposes of strength and ease of manufacture. The

several ribs are shownas substantially horizontal so as to give air openings that are substantially horizontal.

Each opening however is shown as directed into the fuel at an incline somewhat toward the furnace rear, that'is slightly in the direction of the advancing travel of the fuel. This tends better to keep the apertures from obstruction and directs the air more effectively into the fuel. This is due to the fact that the side bars 60 of each twyer member are arranged with their faces, not directly transverse, or at right angles to the length of the retorts, but at a decided incline, as will be perceived by a consideration of Figures 4 to 8. This rearward slant is not claimed as novel herein, and the principles of it are well illustrated in my sa.d patent, although its present use with interpenetrating ribs is new, and conduces to prevention of sifting, especially in connection with the fuel deflector or fin to be described.

Another feature of the present invention is the provision, along the outer edge of each twyer side bar 60, where it faces and contacts the fuel in the retort, an inclined or beveled extension or fin 70, this being so arranged that as the fuel travels rearwardly in the retort the fin 70 operates to thrust the fuel from the twyer member toward the retort, acting like a cam or guard and thus, adjacent to each series of air passages, forcibly deflecting or wedging the fuel from the exits of the air passages, thus tending to keep the fuel out of the apertures and avoiding the tendency to press inwardly and clog them with particles of fuel. This improvement, by keeping the twyer apertures effectively open, ensures a full and proper dis-- tribution and delivery of air into the fuel passing into the retort. More than this, by maintaining a constant flow of air through every partof the twyer structure the metal is kept properly cooled and destruction by burning away is thus avoided. This improvement, therefore, gives increased uniformity and efliciency of combustion and greater durability of apparatus. This fin or deflector might take different shapes. but is shown substantially in all of the-figures of the drawings as consisting simply of an inclined extension or face runningupwardly and downwardly along the outer edge of each of the two opposite'side bars of each twyer member 21 or 22, or in the case of the one-sided structures 23. 24 and 25, along the edge of the single side bar. The deflecting surface slants outwardly toward the rear so as to form a tooth like extension which at the rear edge projects outwardly beyond the exits of the apertures 68. as well seen for example in I igures 7 and 8. Considering the entire bank of twyers the effect of the several fins 70 is to give a saw tooth appearof the air apertures at both sides to protect them from-the pressure of the fuel in the retort. The non-sifting character of the twyersystem of this invention is enchanced "by the fin or guard 70 in that the working of siftings inward along the apertures 68 is more effectively prevented by maintaining these apertures constantly open with a substantial air flow through them.

The twyer members 22 have now been completely described with the exception of the cap pieces which rest upon the apex or ridge of each bank of twyers. Figures 2,

- 3 and 7 show how the opposite side bars fail to meet at their uper ends. The gap or space thus produced is occupied by a series of cap pieces or plates 72, seen in Figures 1 and 2. These cap pieces may be arranged in overlapping order, as shown in Figure 1, and in my said patent, and each is provided with a locking extension 73 which engages under the upper edges of the twyer side bars. The body of each cap. piece may be arched and ribbed as shown and the engagement of each cap piece with the next ,one below may be such as to admit of the delivery of air between the cap pieces upwardly into the fuel, as in my said patent.

Each cap piece may be inserted by turning it at an angle so that the locking extension can drop into place and then swinging the member around into its final position resting upon the one below.

The twyer member 21, shown in Figures 2* and 9, maybe substantially described in the same way as member 22 with the excep tion that member 21 is formed with an integralv apex 75 constituting a continuation of the two opposite side bars 60". The cap 8 pieces arethus dispensed with and on the overlying the twyer members.

.contrary an additional rib or 66" may be added at each side of the member, giving several additional air apertures from the air box into the retort. The topmost rib 66" instead of being of the full dimension of the others may be abbreviated, as indicated by dotted' lines in Figure 9, so as to afford upward air delivery into the fuel Suitable, terminal grate members will. be understood to be provided 'at each end of each bank of twyer members- Thus Figure 1 shows 'aspecial terminal block76at the lower'end of the series of twyers 22 and another special block 77. at the-upper end of the series of twyers 23;

The-twyer 23 is one-sided because itoextends from the extreme retort 42 toward the reduced.

ranged to control neaaaae adjacent sidewall 28 of the furnace. This and the twyer 24 at the opposite side are substantially alike excepting as to theinterior structure, and the details, Figures 12 to 16, may be considered as applying to both. As in my said patent the extreme twyer member-s23 and 2 1 are shown somewhat taller than the intermediate or main twyer members 21 and 22, althoughthis is not essentialas the twyers could all be made of uniform height and means provided in the wall to supply air for combustion, for the protection of the wall and other purposes.

The twyer members 23 and 24, like the members 21 and 22, are provided with inclined side bars 60 or 60, also positioning and 66 or 66 at the rear faces of the bars, the ribs staggered in position so that each ribextends between two ribs of the adjacent bar thus forming a series of apertures 68 or 68 directing air intothe fuel at difl'erent depths. Each bar also is provided with a fin or deflecting extension 70 70 serving to keep open the air assages, as described. The upper ends of t e twyer members 23 and 2d are each formed with an integral apex piece 79 7 9 having positioning lugs 80' or 80 and 81 or 81 for engaging the upper edge of a. casting 82* or 82 which is of l.- shape and forms with the twyer members a hol ow twyer structure resting bodily upon the extreme air box 41. The topmost rear rib 65 (Figs. 12 to 16) is shown extended horizontally across the extension 79 so as to substantially close the twyer structure at the top, but an aperture 83 may be provided as seen in Figures 13 and 15 to permit the upward delivery of air at this point, such airescaping between the top ribs 66 of two I adjacent members.

85 to admit air from the air box into the twyer structure. It is sometimes desirable to regulate thepressures at the upper and lower parts of-the twyer member, for example, to give a greater pressure at the greater depth of fue For this purpose the casting 82 is shown as provided with a partition 86' engaging a lu 87 on the twyer member and formed wit 0 enings 88 for the passage of air, control ed by damper 89% By partly closing the damper the air flow and pressure in the upper chamber is Regulation of per and lower c ambers may be otherwise efl'ected. For example, a wall passage 90 -isindicated leading from the conduit 47 to l the upper chamber and a damper 91 is arsage. v

the flow through this pasv y I no ressure as between the up- The opposite side wall twyer 24 is indicated with a free interior, the L-shaped plate 82 having no partition.

. In the previously described embodiments the air boxes and retorts have been of the stationary or Taylor type. In Figures 10 and 11 the twyer structures and the walls 43 bounding the retorts are of the reciprocating or Riley type. The retort floor 42 may be stationary, but the other parts are methodically moved rearward and forward to assist in the progress of the fuel bed toward the discharge. Figures 10 and 11 show the present invention in this type of furnace grate. The twyer structure 21 may be substantially as already described, as it is relatively stationary, that is, it reciprocates along with the wall 43 that carries it. The extreme twyer members 25 are substantially like the members 23, already described,

although differently supplied with air or fluid of combustion. In Figure 10 the air may enter the lower twyer chamber through the bottom thereof or through a controlled connection 92 from the wall passage 90. The upper chamber may be supplied by regulation of damper 89 or through a separate connection or pipe 93 which may be used to conduct steam rather than air into the upper chamber of the twyer member.

In this modification the side wall 28 is shown as provided with an embedded structure arranged to furnish air to the fuel bed above the twyer member 25, thus assisting combustion and protecting the wall. The twyer member 25 is shown as higher'than the other twyer members. but this need not be so when the aforesaid wall structure is employed. Such structure may comprise a metallic box 96 arranged in a position to be protected from flames. The interior of the box 96 is directly connected with the wall passage 90, controlled by a damper 97 through an exterior handle 98 for regulating the air flow. The box 96 has a perforated partition 99 controlled by a damper 100 and dividing the interior into upper and lower chambers. A series of upright wall members 101 are shown as closing the face of the box 96 and lying flush with the inner surface of the wall 28. These members are arranged to afford air apertures directed into the fuel bed and this may be done by means of a number of ribs 102 at the opposite faces of each member 101, the ribs arranged in staggered relation so as to enter between the ribs of adjacent members, as already explained in connection with the twyer structures 21, 22, etc. The wall members 101 may be either of metal or refactory material and are formed with lugs 103 engaging portions of the partition 99 for holding them in place. Instead of air the wall box 96 may be supplied with steam, or it may be supphed with steam in the upper chamber and air 1n the lower chamber. For this purpose a steam connection 104 is shown controlled by valve 105. The wall members 101 may have fuel deflecting fins 106 like the fins 7 0 of the twyer members 21 to 25.

It will thus be seen that I have described a furnace, furnace grate and twyer system or structure embodying the principles and attaining the objects of the present invention, but as the described embodiment is merely illustrative and many matters of combination, arrangement, construction and detail may be variously modified without departing from the principles, it is not intended to limit the invention to such matters except so far as specified in the appended claims.

Vhat is claimed is:

1. In a progressive feed retort furnace having longitudinal air boxes alongside each retort, a twyer structure upon each air box comprising a bank of separate twyer members in mutual contact, the twyer members consisting of upstanding substantially inverted V-shape castings rest-ing upon the air box and formed to present air apertures between them, directed into the retorts, and each member having an external fin extending up and down along each of its side bars in position to deflect the advancing fuel from the exits of the air apertures.

2. In a progressive feed retort furnace having longitudinal air boxes alongside each retort, a twyer structure upon each air'box comprising a bank of upstanding separate twyer members in mutual contact, each consisting of an A-shapedcasting, the side bars of which rest on the air box, and each side bar having lateral ribs at both front and rear faces, projecting into the spaces between the ribs of adjacent side bars and contacting the bodies but not the ribs of the adjacent bars, thereby forming numerous air apertures directed into the retorts and each side bar formed with a projecting deflector along its length adapted to guard the exits of the air apertures by deflecting the advancing fuel therefrom.

3. In a multiple retort progressive feed furnace having longitudinal air'boxes between which the retorts are formed, a system of twyer structures carried upon the intermediate air boxes, and upon each extreme air box adjacent the furnace wall a twyer structure substantially higher than the first mentioned structures and comprising u standing twyer bars having lateral ri s extending between ribs of adjacent bars to form numerous air apertures, and formed with projecting fins acting to. deflect the advancing fuel from the apertures. a

4. In a progressive feed retort furnace having longitudinal air boxes alongside each retort, and wherein the fuel advances longitudinally through each retort, a twyer structure upon each air box comprising a bank of upstanding separate twyer members in mutual contact, each consistin of an shape casting, the side bars 0 which rest on the air box, and each sidebar having 5' lateral ribs at both front and rear faces, projecting into the spaces between the ribs of adjacent side bars and contacting the bodies of the adjacent bars, thereby form.- ing numerous air apertures directed into 10 the retorts, and each side bar formed at a rearward slant to the length of the retort with its'ribs and spaces also at such slant; whereby a system of air apertures is afiorded each directed at a rearward slant into the fuel bed in the retort and each wholly closed to beneath by one of such projecting ribs.

In testimony vwhereof, l a fixed my signature hereto.

ERNEST B. PRIEBE. 

